Cable operators have widely deployed high-speed data services on cable television systems. These data services allow subscriber-side devices, such as personal computers, to communicate over a cable network. A Modular Cable Modem Termination System (M-CMTS) connects the cable network to a data network, such as the Internet. A downstream Universal Edge Quadrature Amplitude Modulation (UEQAM) located in the cable network receives data transferred over a packet switched portion of the network from the M-CMTS and/or other network devices such as video servers, performs modulation and other processing, and then transfers the modulated data over Quadrature Amplitude Modulation (QAM) channels extending through a constant delay Hybrid Fiber Coaxial (HFC) portion of the cable network.
Some of the data received over the packet switched network is in the form of data streams, such as a Motion Picture Experts Group (MPEG) encoded/compressed video streams. The MPEG data can be CBR (Constant Bit Rate) or VBR (Variable Bit Rate). Because the corresponding modulated data flow for each video stream consumes only a fraction of the available bandwidth of each QAM channel, it is desirable to schedule many of the modulated data flows into each QAM channel in an efficient manner. The disclosure that follows solves this and other problems.